Bo's other son thanks China for allowing father to speak freely: Report

The elder son of ousted Chinese politician Bo Xilai has thanked authorities for allowing his father "to speak his true mind" at his trial and said Bo has stood by his ideas despite an investigation that lasted 500 days, the New York Times said.

Bo put up a feisty defence on Thursday at the start of China's most political trial in decades, saying he was framed in bribery charges against him and had admitted to them under psychological pressure during interrogation.

In a statement posted on the New York Times website late on Thursday, Li Wangzhi, Bo's son from his first marriage, said he has "been subjected to pain and sadness" for Bo, but is proud of his father's strength.

Li attended the trial on Thursday. It was the first time he had seen Bo in several years, according to the New York Times.

"I thank the party central authorities and the court for giving the defendant greater rights to a defense and freedom than he had expected, allowing my father to speak his true mind," Li said.

Bo's denial of the charges and strong language as he made his first public appearance since being ousted early last year were unexpected. But observers said he could have agreed to choreographed proceedings that would show authorities in an impartial light in exchange for a pre-arranged sentence.

The 64-year-old former Communist Party chief of the southwestern city of Chongqing has been charged with illegally taking almost 27 million yuan, corruption and abuse of power and will almost certainly be found guilty.

"After undergoing a worldwide investigation involving in excess of 300 people and 500 days, he has endured a tremendous test, and nonetheless has stood by his ideas," Li said. "True gold does not fear fire."

Li said he hopes the law will "leave the people an explanation, leave history an explanation, and leave his son an explanation too."

On Tuesday, Bo's other son, Bo Guagua, urged authorities to grant his father the opportunity to defend himself ahead of his trial. Guagua, who is in the United States pursuing a law degree at Columbia University, said he has been denied contact with his parents for the past 18 months.

Bo's wife and Guagua's mother, Gu Kailai, and his police chief, Wang Lijun, have both been jailed over a scandal stemming from the November 2011 murder of British businessman Neil Heywood in Chongqing.